Solution Structure of pA2, the Mimotopic Peptide of Apolipoprotein A-I, by NMR Spectroscopy

Abstract

A number of mimetic peptides of apolipoprotein A-I, a major component for high density lipoproteins (HDL), were screened from the phase-displayed random peptide library by utilizing monoclonal antibodies (A12). A mimetic peptide for A12 epitope against apolipoprotein A-I was selected as FVLVRDTFPSSVCCP(pA2) exhibiting 45% homology with Apo A-I in the BLAST search. Solution structure determination of this mimotope was made by using 2D-NMR data and NMR-based distance geometry (DG)/molecular dynamic calculations. The resulting DG structures had low penalty value of 0.4-0.6 angstrom(2) and the total RMSD of 0.7-1.7 angstrom. The mimotope pA2 exhibited a characteristic beta-turn conformation from Val[2] to Phe[8] near Pro[9] residue.